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Strawberry Fertiliser and Crop Nutrition

strawberry fertiliser and crop nutrition
close up of many strawberries

UK Strawberries

Strawberries, both Ever Bearers and June Bearers, require a balanced programme of nutrition. The nutritional programme should focus on rooting, plant health, quality and yield of the strawberry crop.

Key Nutrients in Strawberry Production:

Key strawberry macronutrients include: N, P, K, Ca, Mg, S

Key strawberry micronutrients include: Fe, Mn, B, Mo, Zn, Cu, Si

Download Strawberry Feed Programme
strawberry flower

Strawberry Fertiliser

NPK Strawberry Fertiliser: Strawberries, as with most crops, require a dose of macro nutrition in the form of nitrogen, phosphorus and potassium. Nitrogen in the strawberry crop is essential for plant growth.

Phosphorus is important in early establishment. Potassium is required in larger quantities within the strawberry crop to aid with fruit formation. OMEX offer fully water soluble powders in the form of the O-Mix Soluble Powder Range.

In the early stages of establishment an O-Mix 18-18-18+TE grade is recommended and a O-Mix 6.5-11-30+TE grade is recommended at the later development stages to provide the crop with its much needed potassium requirement.

Calcium in Strawberries

Calcium is vital in the production of strawberries, it promotes good plant health, fruit firmness and shelf life.

Calcium is a key signalling nutrient, allowing effective pollen tube growth and fertilisation of the ovary. Poor movement of calcium at this time can lead to unsuccessful pollination.

Growers can provide their crops with a healthy dose of calcium in the form of CalMax Ultra. CalMax Ultra contains calcium in conjunction with a ‘pump primer’ that ensures the calcium can be actively transported into plant cells even during the difficult periods of low metabolic activity and stress.

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CalMax Ultra provides the crop with quality calcium liquid fertiliser

Improved calcium levels
Protects against calcium related disorders
Increases brix levels
CalMax Ultra
mould development room graph

Longer Shelf Life

Improving strawberry shelf life: OMEX have researched the use of CalMax Ultra applied immediately pre-harvest to improve shelf life. The trial looked specifically at mould and mildew development on the treated v untreated strawberries.

The CalMax Ultra treated strawberries reduced the risk of mould/mildew compared to the untreated control.

Improving strawberry fruit firmness: CalMax Ultra has been demonstrated to improve the fruit firmness of strawberries

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Improving marketable yield of strawberries

This trial looked at utilising Kelpak as a root dip treatment on strawberries plants at transplant.

The Kelpak 1% treatment yielded 59.06g more than the control (+15%.)
The Kelpak 2% treatment yielded 118.97g more than the control (+30%)
This shows a strong dose response trend. There was double the yield increase from 2% Kelpak compared to the 1% Kelpak treatment.

The Kelpak 1% treatment gave 140.5g more marketable yield than the control (+51%).
The Kelpak 2% treatment gave 197.53g more marketable fruit yield than the control (+72%).

strawberries graphs
Trial Results

Again, this shows a strong dose response trend within the Kelpak treatments, significantly improving the marketable proportion of the yield, therefore increasing profitability and reducing wasted fruit.

The trial demonstrated improved canopy and leaf development along with total fruit numbers and marketable fruit numbers.

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strawberries growing in a polytunnel

Magnesium in Strawberries

Magnesium is an element which is essential for several plant functions. Magnesium plays a major role in the process of photosynthesis. It is also involved with a number of enzyme systems and the movement of sugars from leaves to the rest of the plant.

Magnesium deficiency is usually found on the older leaves of plants as an interveinal chlorosis. When severely deficient, leaves can abort and fall off. Spotting or interveinal yellowing are the first symptoms. If not dealt with efficiently the problem will move upwards, affecting other parts of the plant. Magnesium deficiency will seriously affect crop growth, quality and yield because the crop will not be able to photosynthesise effectively.


Magnesium is included within O-Mix water soluble blended fertilisers at a rate of 1.6-5.0% depending on the grade selected, but additional magnesium can also be applied either as a foliar feed or added to stock tank B when a crop supplement is needed.

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soft fruit fertiliser | OMEX
Folex Mg 13

Folex Mg 13 is a 13% MgO magnesium nitrate option for application to a crop usually during the vegetative phase and Folex Mg 9 is a 9% MgO magnesium sulphate option for use during the generative phase.

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Biostimulants for Strawberries

Biostimulants are playing an increasingly important role in optimising the performance of strawberry crops, ensuring that canopy is functioning as efficiently as possible to move dry matter to where it is needed most, and most profitably, i.e. the fruit. Kelpak from OMEX has repeatedly shown to improve yield, on third party trial sites (12% improvement compared to a control), and in UK grower trials against an untreated control by 9% and against competitor products by 2.5%.replicated trials as seen in the data.

kelpek strawberry trial
Kelpak Strawberry Trial

The above trial shows strawberry yield performance compared to an untreated control in 2018 and 2021 and compared against a commercial alternative in 2022. Yield was improved by 12% in 2018, 9% in 2021 and 2.5% in 2022 by Kelpak.

Read about further Kelpak trials on strawberries.

Kelpak Strawberry Trials
strawberries tabletop
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